This invention generally relates to elevator control systems. More particularly, this invention relates to a key access device for directing an elevator cab to a specific landing.
Most elevator cabs travel within a hoistway between landings at different levels in a building. Typical passengers obtain access to the elevator cab by using a hall button. When there are multiple elevator cabs within multiple hoistways within a building, activation of a hall button typically results in at least one elevator cab arriving at the landing to allow a passenger access.
There are also times when a technician needs access to an elevator cab to perform maintenance or repair. For these instances, key access switches have been used that allow a technician to gain access to the cab. A difficulty associated with conventional key access switches is that they only control cab position after the technician has access to the cab at a desired landing. The technician must rely on the passenger hall buttons, which are not specifically dedicated to a particular elevator cab, to get the desired cab to a landing. In buildings where there are multiple hoistways and multiple cabs, a technician may not obtain access to the desired cab until multiple attempts are made because the elevator system randomly sends a cab to the landing where the technician desires access. This proves frustrating where multiple hoistways are present and the technician needs access to a particular elevator cab.
This invention addresses the need for an improved access system by providing a key access switch that provides the desired results each time upon a first try.
In general terms, this invention is a device for providing specific access to an elevator cab within a building regardless of the number of hoistways or elevator cabs that are present. The inventive device includes a switch that is selectively activated to generate a signal indicating a desire for access to a specific elevator cab at a specific landing. A controller communicates with the switch and directs the appropriate elevator cab to the appropriate landing.
The inventive switch also includes the ability to operate in an inspection mode to selectively move the elevator cab up or down a selected amount within the hoistway during a maintenance procedure.
The various features and advantages of this invention will become apparent to those skilled in the art from the following detailed description of the currently preferred embodiment. The drawings that accompany the detailed description can be briefly described as follows.